Valve mechanism for hydraulic elevators.



Pat-nted May 27, I902. H. F. WITTE. VALVE MECHANISM FOR HYDRAULICELEVATORS.

(Application filed Sept. 5. 1899.1

2 Sheets-Shaet I.

(No Model.)

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No. 700,877. Pat anted May 27, 1902.

H. r. WITTE.

VALVE MECHANISM FOR HYDRAULIC ELEVATORS.

' A xicaeion filed Sept. 5, 1899.: (N Model.) ZSheets-Shaet "n uonmsPETERS cc. mom-urns" WASHINGTON n c UNITED STATES PATENT OFFICE.

HERMAN F. WITTE, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE OTIS ELEVATORCOMPANY, OF EAST ORANGE, NEW JERSEY, A CORPO- RATION OF NEW JERSEY.

VALVE MECHANISM FOR HYDRAULIC ELEVATORS.

SPECIFICATION formingpart of Letters Patent No. 700,877, datedMay 2.7,1902. Application filed September 5, 1899. SerialNo. 729,433. (Nomodel.)

T0 at whom, it may concern:

Beit known that I, HERMAN F.WITTE,a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Valve Mechanism for Hydraulic Elevators, ofwhich the pilot-valve, through which the main valve and the power-valvewhich actuates it are controlled, is subjected to the action of a lowhead or pressure.

A further object of the invention is to provide means whereby thepressure controlled.

by the pilot-valve is independentof the pressure of fluid-supply to themachine.

A further object of the invention is to relieve the pilot-valve'of unduewear resulting from a high-pressure power to be controlled thereby.

Other objects of the invention will appear more fully hereinafter.

The invention consists, substantially, in the construction, combination,looation,-and arrangement, all as will be more fully hereinafter setforth, as shown in the accompanying drawings, and finally specificallypointed out in the appended claims.

Referring to the accompanying drawings, and to the various views andreference-signs appearing thereon, Figure l is a view in side elevation,showing the arrangement of a hydraulic-elevator hoisting apparatus andthe application of the invention thereto. Fig. 2 is an end elevation ofthe valve devices for controlling the hoisting mechanism. Fig. 3 is anenlarged view, in central longitudinal section, of the valve mechanism,parts being shown in side elevation and embodying the principles of theinvention.

The same part is designated by the same reference-sign wherever itoccurs.

Heretofore in the operation of valvemechanisms for hydraulic elevatorsit has been the usual custom to operate the power-piston, through whichthe movements of the main or reversing valve are effected, by the samehead or pressure of fluid-supply employed for effecting the movements ofthe car-that is, the same head or pressure of fluid supplied to themachine-and consequently the pilot-valve employed in connection with thevalve mechanism has been required to control this high pressure, withthe result that by reason of the smallness of the pilot-valve leakagequickly develops through wear of the packing thereof under the action ofthe high pressure of the fluid-supply, which said valve is required tocontrol and to which it is subjected. It is difficult to eificientlypack the pilotvalve, by reason of the smallness of its size, to resistthe effects of the high pressureand to prevent leakage and at the sametime to permit the proper adjustments to be made. This has proven to bea defect-in practice which it is exceedingly desirable to avoid andovercome, and it is the special purpose of the presentinvention toprovide a construction and arrangement of valve mechanism wherein thepilot-valve is relieved of the high pressure which is supplied to thehoisting-motor and is operated with a low pressure, thus avoidingimpairment of the efliciency of the packing of said valve, and henceavoiding objectionable leakage. The pres sure-supply, through which thepower-piston for actuating the main or reversing valve is operated, andhence the pressure which the pilot-valve is required to control, may bede, rived from any suitable or convenient source in the application ofthe principles of my invention. For instance, this pressure or supplymaybe derived from an ordinary housetank or from the usual citywater-supply, or it may be taken from the operating system of theelevator hoisting mechanism, but at a reduced-pressure, or this pressuremay be derived from any other suitable or convenient source, theimportant feature beingthat a low pressure of fluid-supply is employedfor this work, while a high pressure is required for the hoisting-motor.

Referring to the accompanying drawings,

illustrating an operative construction and arrangement for carrying outthe principles above outlined, reference-sign A designates a car; B, themain cylinder, to the plunger of which the car is suitably connected; 0,the mo automatic stop-valve; D, the accumulator, and E- thedischarge-tank. These parts may be of the usual or anywell-knowln'suitable, or convenient type of hydraulic-elevatormechanism, and the particular construction and arrangement thereofrequire no special description.

Reference-sign F designates the pipe whicl v is connected to thedischarge side of the main pump, through which the required pressure ofoperating fluid for the hoisting-motor is secured, and G designates thepipe connecting to the opposite side of the pump. These pipes areordinarily known as the pump discharge and the pump suction pipes. Thepipe F delivers into the main reversing-valve H, as clearly shown inFigs. 1 and 3. The fluid after passing through the reversingvalve enterspipe J from such valve and then, passing through the automaticstop-valve C and pipe K, finally delivers into the main cyl-' inder B.The exhaust from the main cylinder B'passes back through pipe K,automatic stop 0, pipe J to the reversing-valve H, thence through pipe Linto the discharge-tank E and thence through pipe M to the pumpsuctionpipe G, thus completing the system.

Now in carrying out the principles of my invention instead of operatingthe power-piston, through which the main reversing-valve is actuated, bypressure drawn from the pump discharge-pipe F and then returning ordis-- charging such pressure after it has accomplished its purpose ofactuating said powerpiston back into the. pump suction-pipe G, as hasheretofore been the usual custom, I supply an operating medium toactuate said power-valve at a low pressure from some other suitable orconvenient source, as above explained. For instance, and by way ofillustration, the supply of operating fluid for the power-cylinder maybe drawn from the pump suction-pipe G through a suitable connec tion N,and the discharge from said powercylinder is effected through a pipe 0into a suitably and conveniently arranged tank P. The supply ofoperating fluid through pipe N to the power-cylinder Q is controlled bythe pilot-valve R, and the discharge from the power-cylinder Q iseffected through the pipes S T, respectively, communicating with theends of said power-cylinder, said pipes S and T finally joining anddelivering into pipe 0 and thence into tank 1?.

The operation is as follows: When the pilot-valve R is actuated in theusual or any convenient manner from the car in a direction to open thesupply-pipe N to one or the othersay the right-hand-end of thepowercylinder Q, the operating medium under low pressure is admitted tothe right-hand end of the power-cylinder and causes the power-piston Wto move toward the left-hand end of said cylinder, the same movement ofthe pilot-valve which admits the low-pressure medium to the right-handend of the cylinder also uncovering the exhaust-port at the leftthe stemE of the pilot-valve.

der effects a coincident movement of the main reversingvalve H throughanysuitable connect-ions, thus opening communication be tween themachine supply-pipe J and the discharge pipe L. This action opens themain cylinder B to the discharge, and the operatin g medium is exhaustedfrom said main cylinder B, through pipe K, automatic stopvalve 0, pipeJ, discharge-pipe L, into discharge-tank E. The exhaust of the maincylinder B is effected by the over weight of the car A, said exhaustresulting in the lowering of the car. Similarly, when the pilotvalveRismoved in the opposite direction, so as to open supply-pipe -N to theleft-hand end of the power-cylinder Q, the right-hand end of saidcylinder is opened to exhaust through pipe T, and thence through pipe 0into tank P. At the same time the power piston W is moved toward theright-hand end of the power-cylinder, and through its connection withthe main reversing-valve H said valve is moved to open communicationbetween pipe F and pipe J. Thereupon the operating medium from thepump-discharge is admitted through pipe F, through the reversing-valve Hto the machine supply-pipe J, thence through the automatic stop-valve G,pipe K, and into cylinder B, thereby effecting the raising of the car.

The pilot-valve may be actuated in any suitable manner from the car. Inthe particular form shown, to which, however, the invention is notlimited, an arm A is provided and adapted to be rocked from the car--as, for instance, by being mounted on a rock shaft B, which may berotated from the car through the hand-cable or other suitableconnections in a well-understood manner, as indicated in dotted lines inFig. 3. The arm A is connected by means of alink C to a pivoted yoke'D,to which is pivotally connected The particular form of connectionbetween the piston WV and the reversing-valve H is unimportant so far asthe present invention is concerned. In

the particular form shown, to which the invention is not limited, thestem F of said piston is connected to the tubular valve-stem G of thereversing-Valve through arms H, whereby said valve-stems are connectedto move coincidently and in unison, and, if desired, the yoke D may bepivotally connected to one of the arms H, thus tending to restore thepilotsvalve to its cut-ofi position when the power-piston NV andreversing-valve H approach the limits of their movement in eitherdirection. However,the particular construction and arrangement ofdevices for actuating the pilot-valve and for securing coincidentandsimultaneous travel of the power-piston W and reversing-valve H formno part of the present invention and may be varied, al-

tered, or changed, as may be desired, without afiecting the scope of myinvention. Similarly the construction and arrangement of the lator Dbeing connected through pipe J to the supply-pipe F.

From the foregoing description it will be seen that in the particularform shown, to which, however, the invention is not limited, the mediumfor operating the power-piston W is taken from the pump suction-pipe G,and the pressure of which may be from fifty to two hundred pounds persquare inch, whereas the pressure of the operating medium, which passesthrough the main or reversing valve H, is usually about seven hundredand fifty pounds per square inch. It will also be seen that in theconstruction and arrangement shown and described the powercylinder Qdischarges into a tank P. In order that the fluid employed for actuatingthe power-piston may not be wasted, the medium delivered into tank I maybe returned into the circulating system, if desired, and in any suitablemanner, as by means of an injector or other suitable arrangement. In theparticular form shown an auxiliary pump K isemployed for dischargingfrom the tank P through pipes L and M into pipe L, which discharges intodischarge-tank E of the system. It is obvious, however, that instead ofdrawing the supply of operating medium for the power-piston WV from thecirculating system of the apparatus it may be drawn from any othersource, as from a separate tank suitably supplied or from the city watersystem, and in any event the discharge of such power-piston operatingmedium may be permitted to go to waste, if desired. It is also evidentthat the principles of my invention may be applied where the operatingmedium is steam, the essential feature being that the operating mediumfor the power-piston and which is under the control of the pilot-valveis of large volume and comparatively low pressure, while the mediumwhich actuates the hoisting-motor is of comparatively small volume andlarge or high pressure.

I have found in the practical operation of my invention, wherein thepilot-valve is required to control a low pressure, that leakage isavoided and that said pilot-valveis more easily actuated and the carresponds more quickly and uniformly to the operation of the hand-leveror control-cable on the car.

Many variations and changes in the details of construction andarrangement would readily suggest themselves to persons skilled in theart and still fall within the spirit and scope of my invention. I do notdesire, therefore, to be limited or restricted to the particular form ofconstruction and arrangement of devices shown and described. It is alsoobvious that the associated operating parts maybe varied, altered, andchanged in the details of their construction and arrangement withioutaffecting the principles of my invention; but,

Having now set forth the object and nature of my invention and anoperative embodiment of the principles thereof, what I claim as new anduseful and of my own invention, and desire to secure by Letters Patentof the United States, is

1. In a hydraulic-elevator hoisting mechanism, a hoisting-cylinder, areversing-valve for controlling the supply to and exhaust from saidcylinder of an operating medium at high pressure, a discharge-tank forsaid hoisting-cylinder, a power-cylinder, a pistonarranged therein andconnected to said reversing-valve for actuating the lattelgpipesdelivering from said discharge-tank into both ends of saidpower-cylinder, whereby an operating medium at low pressure is deliveredinto either end of said power-cylinder to operate said piston in bothdirections, a pilotvalve for controlling said pipes, and means forreturning the exhaust from said powercylinder into said discharge-tank,as and for the purpose set forth;

2. In a hydraulic-elevator hoisting mechanism, a circulating systemfor ahigh-pressure operating medium, a main or reversing valve forcontrolling said system, a powercylinder, a piston operating therein, alowpressure hydraulic supply, pipes delivering from said supplyinto'said power-cylinder, a pilot-valve arranged to control theadmission of said low-pressure mediumto either end of saidpower-cylinder at will, to voperate said piston in either direction, andmeans whereby the discharge of such low-pressure operating mediumisreturned into the circulating system, as and for the purpose set forth.

3. In a hydraulic-elevator hoistingmechanism, a circulating systemforahigh-pressure operating medium, a main or reversing valve forcontrolling said system, a power-cylinder,a piston operating therein, alow-pressure hydraulic supply,.pipes delivering from said supply intosaid power-cylinder, a pilotvalve arrangedvto control the admission ofsaid low-pressure medium to either end of said power-cylinder,manually-operated means for moving said pilot-valve in either directionto open eitherend at will of said powercylinder to the source oflow-pressure supply to operate said piston in either direction,connections between said piston and said reversing-valve, and meansactuated'by the movement of said reversing-valve for moving saidpilot-valve to close communication with the source of low-pressuresupply of said cylinder and to, open said cylinder to exhaust, as

and for the purpose set forth. I

4. In a vvalve mechanism for elevators, a main reversing-valvearrangedto control the supply of high-pressure, operating medium to and from thehoisting-motorfln combination with a cylinder, a piston-arranged thereinand connected to said reversing-valve for operating the latter, avalve-chest, a low-pressure hydraulic supply, pipes delivering from saidsupply to said chest, an exhaust-pipe also communicating with saidchest, ports arranged to open communication between said chest and eachend of said cylinder, a pilotvalve for controlling said ports,manuallyoperated devices for moving said valve to open said ports, andmeans operated by the movement of said piston for automatically movingsaid pilot-valve to close said ports and to open said cylinder-exhaust,as and for the purpose set forth.

5. In a valve mechanism for hydraulic elevators, a hoisting mechanism, amain or reversing valve arranged to control the supply of high-pressure,operating medium to and from the hoist-motor, a power-piston foroperating said valve, a cylinder in which said piston operates, a sourceof low-pressure hydraulic supply for said power-cylinder, ports arrangedto deliver into each end of said power-cylinder and to each side of saidpiston, a pilot-valve for controlling said ports, manually-actuateddevices for moving said pilot-valve in either direction to open eitherend of said power-cylinder to the source of low-pressure supply, andmeans actuated by the movements of said piston for moving saidpilot-valve to close said cylinder to the source valve, said portsleading to a different and independent source of supply from that of thehoisting-motor, means for manually moving said pilot-valve ineitherdirection at will to open said cylinder to its independent sourceof supply, and means actuated by the movements of said piston when saidpilot-valve is moved in either direction for automatically moving saidpilot-valve in the opposite direction to close said cylinder to itssource of supply and to open the same to exhaust, as and for the purposeset forth.

In witness whereof I have hereunto set my hand, this 30th day of August,1899, in the presence of the subscribing witnesses.

HERMAN F. WITTE.

Witnesses:

HENRY H. DAHLMAN, S. E. DARBY.

